>> and, chuck, another illustration of the dark days that can come to the president. whoever happens to be the president at any given time. last time we saw the president kind of in this cast was days before christmas, that terribly sad announcement after newtown. >> reporter: it was. you know, it's interesting the different tone. you could hear and feel the frustration with the president this time. in the newtown days and just how much of a gut punch. you could see the emotion with the president there. here, you can see and feel and hear the determination and, frankly, the frustration in his voice about the lack of what they know about what happened, who did this, and why. i can tell you in talking with various security officials they are frustrated. they are not used to even four hours after something like this happens to know as little as they seem to know tonight. >> chuck todd on the white house north lawn for us tonight. chuck, thanks.